Microwave-assisted synthesis of triazine covalent organic frameworks via friedel-crafts reaction for use in treating brackish Water

Abstract

Water scarcity is becoming an ever-growing problem in society. This is all due to the rapid increase in human population, harsh changes in the weather climate. New approaches for treating and recycling brine water into freshwater instead of discharging are needed, significantly large reduction in energy usage and decreasing harmful impact to the environment must be achieved in brine recovery. This study aims to introduced green technology into the reclamation of brine water by use of covalent organic frameworks (COFs) materials which will be used as part of a novel triazine-based COFs material which can be used as a nanomembrane for desalination of brine water from water treatment plants at Umgeni Water. Current technological approaches used are inefficient and unsuitable in 3rd world, developing countries including the republic of South Africa. This work focuses on a microwave-assisted synthesis involving Friedel Crafts reaction between monomers to yield a product of a triazine-based covalent organic frameworks (COFs) membranes. To confirm the products high resolution transmission electron microscopy (HRTEM), carbon NMR (13C NMR) with peaks at chemical shifts of 131, 143 and 172 ppm respectively. Fourier-transform infrared spectroscopy (FTIR) was employed and showed N-H stretches at a region of 3396 to 3050 cm-1. The COFs that were successfully synthesised are going to be incorporated on a polymeric substrate to fabricate a nanofiltration membrane and applied for nanofiltration or ultrafiltration purposes.